qa/admin/check-manifest: refine hackaround for very odd setup on test-ubuntu2004-direct/1282
qa/admin/check-manifest: refine hackaround for very odd setup on test-ubuntu2004-direct/1282

This machine ends up with /bin being a symlink to usr/bin which means
"which bash" -> /usr/bin/bash which does not match the packaging that
thinks the bash executable should be in /bin.

adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp